WATKINS GLEN, New York – The historic and challenging Watkins Glen International, with its high-speed corners and elevation changes, tests the limits of even the fittest Verizon IndyCar Series driver.

Tackling the undulating 11-turn, 3.37-mile circuit in upper New York State after a long layoff due to injury might not strike fear in the heart of Sebastien Bourdais, but the task certainly commands his respect.

“The Glen is very high-grip track and a physical one for us in an Indy car, so I don't expect it to be easy, but I think I should be able to manage hopefully,” said Bourdais, who started his first race at Gateway Motorsport Park on Aug. 26 after recovering from a May accident in qualifying for the Indianapolis 500.

“I think the slowest corner at the Glen is 90 mph, so it's really just high commitment, high speeds, high G’s and high steering effort pretty much everywhere. For sure, the right-hander after the Bus Stop going down the hill is almost flat if your car is perfect and it lasts a long time. So it's high load, but it's more the accumulation than one specific corner that gets you.”

Bourdais feels he's back to about 90 percent in general physically, but that goes up to around 95 percent in the car. The four-time Indy car champion plans to use some padding and make other small adjustments in the cockpit to help him contend with the high G-forces.

“It should be fairly easy to find a compromise that's workable and that I don't have to feel I am giving up performance in the car,” said the No. 18 UNIFIN Honda driver for Dale Coyne Racing.

“I have to get back into the groove anyways and physically, like heart-wise and cardio-wise, I am pretty good, it's just obviously all the little muscles, the forearms, the neck and things like that where it's always difficult to know where you are at.”

While Bourdais is getting back to work after sustaining fractures to his hip and pelvis in the May crash, rookie Jack Harvey (left) faces a different challenge. The six-time Indy Lights winner signed a two-race deal with Schmidt Peterson Motorsports to run the No. 7 AutoNation Honda at Watkins Glen and the season-ending GoPro Grand Prix of Sonoma on Sept. 17.

The only time Harvey started a Verizon IndyCar Series race was the 101st Indianapolis 500 in May, where he was caught up in another driver's accident and retired after 65 laps. Jumping into an Indy car at a track that pushes drivers’ strength and conditioning to the limit certainly isn't something he's taking lightly, either.

“I would be lying if I said it wasn't something I was worried about,” said Harvey, adding he hasn’t driven on a road course in a year.

“I'm hoping it's like riding a bike and muscle memory and all that jazz, but honestly I've tried to stay as prepared as possible and I've done some simulator days, so I feel pretty prepared for this opportunity.”

Harvey expects to be “a little sore,” especially after today’s practice sessions. He feels his neck will take the most punishment. Stepping up his physical fitness program in preparation for the race will help, he insisted, but nothing compares to the G forces exerted on the body in the cockpit.

“I think it’s just getting back in the car and letting it happen naturally — it's hard to force these things,” Harvey said. “This race will push the cobwebs off, as it were, and hopefully I'll be more physically ready for Sonoma because I will have actually driven the car as opposed to being physically ready now but not having driven the car.”

Bourdais agreed, saying that the mental and physical short oval training from a week ago went a long way to preparing him for this weekend at one of the most demanding circuits on the 2017 Verizon IndyCar Series schedule.

“I think I got a good workout at Gateway. The car was not easy to drive, steering effort was pretty high, for sure, so towards the end of the race it was not easy. But I think I'll be OK. I wasn't particularly tired,” he said.

“At the end of the day, the short oval at the speeds we are doing them means you have to hit your marks and be right on the money. I think it was a good thing that I got back for Gateway because it will help me both physically and mentally to be ready for Watkins Glen.”

Practice continues at 3:05 p.m. ET today, with knockout qualifying set for 3 p.m. Saturday. Both will stream live on RaceControl.IndyCar.com. Live coverage of the 60-lap race starts at 1 p.m. Sunday on NBCSN and the Advance Auto Parts INDYCAR Radio Network.